1. Field of the Invention
The present invention relates to a cruise control device of a motor vehicle, more particularly to a cruise control device of a pulling cord reel used in different models of motor vehicles.
2. Description of Related Art
As the performance of motor vehicles is enhanced unceasingly, the motor vehicles nowadays provide different cruise control devices or speed control systems for keeping the speed of a motor vehicle constant. Such system automatically changes the throttle position in the carburetor or air manifold according to the change of road conditions and keeps the speed of the motor vehicle in a predetermined speed.
A cruise control device adopted by traditional motor vehicles general keeps the movement of motor vehicles in a constant speed by means of a vacuum service converter installed between a vacuum storage tank and a vacuum driving device that are coupled to the air manifold of the engine. However, if this kind of speed controller runs into a road condition having big changes, then it will give rise to a severe change to the position of the throttle and a significant drop in engine performance, meanwhile the constant speed controller also reduces the degree of vacuum of the air manifold, and thus causes a significant drop in engine performance. The previous automatic speed of a motor vehicle or the constant speed control system has been described in the U.S. Pat. No. 3,485,316 entitled xe2x80x9cAutomobile Speed Controlxe2x80x9d by Slavin, et al issued on Dec. 23, 1969, and the U.S. Pat. No. 4,170,274 entitled xe2x80x9cDevice for Regulating the Traveling Speed of a Motor Vehiclexe2x80x9d by Colonia issued on Oct. 9, 1979.
Furthermore, many of the currently known cruise control devices used in automobiles comprise a pulling cord reel, being coupled to a throttle link rod by a pulling cord; a driving motor for providing the required displacement of the throttle when the automobile is accelerated or retarded; and a clutch for engaging or detaching the pulling cord reel to/from the driving motor. However, there are changes in specific speeds for different automobiles, and the displacements required by the throttles are different. Therefore, if the same cruise control device is installed in different models of automobiles, it generally cannot match with the speed control mechanism. In another word, it will create the situation of accelerating too fast or retarding too slowly, or even not able to accomplish the predetermined speed.
The prior art also provides a cruise control device for motor vehicles, which makes use of a swinging arm to pull a pulling cord connected to the speed control mechanism of the motor vehicle. By changing the length of the swinging arm, the cruise control device can be installed to different models of motor vehicles. However, when such swinging arm pulls the pulling cord, the pulling force generated will be different according to the different angle of the swinging arm. Therefore, it usually cannot control the speed of the motor vehicle properly. Further, as the pulling cord changes its position according to the swing arm, the pulling cord will be twisted when the swinging arm is reversed. That will damage the cruise control device of the motor vehicle.
In view of the aforementioned shortcomings of the prior arts, there is a need for a cruise control device for motor vehicles that can be used in different models of motor vehicles, and can match with the speed control mechanism of such motor vehicle for controlling the speed of the motor vehicle.
The primary objective of the present invention is to provide a cruise control device of motor vehicle with adjustable traveling distance of pulling cord reel, which is installed in the cruise control device of the motor vehicle and such cruise control device can be installed in different models of motor vehicles and match with the speed control mechanism of such motor vehicle.
The secondary objective of the present invention is to provide a cruise control device of motor vehicle with adjustable traveling distance of pulling cord reel capable of smoothly moving the pulling cord between the constant speed deice and the speed control mechanism of the motor vehicle.
To attain the foregoing purpose, the cruise control device of motor vehicle with adjustable traveling distance of pulling cord reel according to the present invention is installed in a motor vehicle, and the motor vehicle is driven by an internal combustion engine having a speed control mechanism; the cruise control device of the motor vehicle comprising a running gear, a clutch, a pulling cord reel, and a pulling cord, characterized in that said pulling cord reel comprises: two side walls for forming a groove to accommodate the pulling cord; a middle section having at least two arcs with different radii; wherein the running gear of the cruise control device of the motor vehicle can detach the pulling cord reel by the clutch; an end of the pulling cord is coupled to the pulling cord reel, and the other end to the speed control mechanism; such that the installation of such pulling cord reel can be reversed, and the traveling distance for the cruise control device of the motor vehicle can easily be changed.
According to another characteristic of the cruise control device for motor vehicle with adjustable traveling distance of pulling cord reel of the present invention, the middle section of the pulling cord reel is a spiral.
According to another characteristic of the cruise control device for motor vehicle with adjustable traveling distance of pulling cord reel of the present invention, the cruise control device has a fixing device for fixing the pulling cord and a leading wall for leading the direction of the pulling cord.
By the arrangement of the cruise control device of motor vehicles with adjustable traveling distance of pulling cord reel of the present invention, the cruise control device for motor vehicle can be installed in different models of motor vehicles easily for its application, and can match with the speed control mechanism of the motor vehicle.